Clamp connector for clamping together connecting pieces on pipelines

ABSTRACT

A clamp connector for clamping together connecting pieces ( 5 ) on pipelines, having two clamping ring parts ( 1, 3 ) which are connected at one end by means of a joint arrangement ( 11 ) and which are pivotable about said joint arrangement ( 11 ) between spread positions and clamping positions in which said clamping ring parts ( 1, 3 ) are situated close to one another, and having a clamping device which is situated at the opposite end of the clamping ring parts ( 1, 3 ) from the joint arrangement ( 11 ), which clamping device has a clamping screw ( 19 ) which can be pivoted from an active position, in which said clamping screw ( 19 ) interacts with the clamping ring parts ( 1, 3 ) in order to generate a clamping force which presses said clamping ring parts ( 1, 3 ) into the clamping positions, and a release position in which said clamping screw ( 19 ) is pivoted away from said clamping positions and in which the clamping ring parts ( 1, 3 ) are released, is characterized in that the clamping device has a locking device ( 25, 27 ) which, in the active state thereof, prevents the clamping screw ( 19 ) from being pivoted out into the release position and which, as a function of the spread of the clamping ring parts ( 1, 3 ), passes through a predefined opening angle from the active state into a release state in which the clamping screw ( 19 ) can be pivoted out.

The invention relates to a clamp connector for clamping togetherconnecting pieces on pipelines, with two clamping ring parts which areconnected on one end by means of a joint arrangement and which can pivotaround said joint arrangement between the spread positions and clampedpositions in which said clamping ring parts are situated close to oneanother, and with a clamping device that is located on the end of theclamping ring parts opposite the joint arrangement, the clamping devicehaving a clamping screw which is pivotable from an active position inwhich it works together with said clamping ring parts to generate aclamping force that forces the clamping ring parts into the clampedpositions and a release position which is pivoted out therefrom.

Clamp connectors of this type are known. For example, according to DIN(© DIN: Deutsches Institut für Normung e. V. [German Institute forStandardization, Registered Association]) 32676, clamping connectionswith such clamp connectors for fittings for the food, chemical, andpharmaceutical industries are standardized and, in fact, for arelatively large range of nominal sizes. In the case of such clampconnectors, the clamping rings work together with clamping connectionpieces that can be connected as, for example, welded connection pieceswith corresponding pipe ends, in such a way that the axial force forclamping the connecting pieces together is generated by a radialclamping force acting on them by means of oblique surfaces that areinclined on the connection pieces with respect to the longitudinal axisof the pipe.

Since, according to the applicable standards provisions, such clampconnectors are usable at pressures of up to 16 bar, even with largenominal widths, there are special requirements as regards operatingsafety.

Therefore, the stated object of the invention is to make available aclamp connector of the type under consideration that offers a highdegree of operating safety during handling, especially when an elevatedlevel of pressure is involved.

According to the invention, this object is accomplished by means of aclamp connector having the features of claim 1 in its entirety.

Accordingly, one essential particularity of the invention lies in thefact that the clamping device is equipped with a locking device thatacts as a safety mechanism which allows the clamping screw to pivot awayonly when, during a working cycle in which the clamping connection isseparated, the clamping ring parts are initially spread out from theclamping position through a predetermined opening angle. This avoids therisk that even a slight loosening of the effective tightening of theclamping screw could cause the screw to pivot out of the activeposition, thus leading to a sudden loosening of the connection underpressure, with the concomitant risks associated therewith.

In especially advantageous embodiments, the arrangement can be designedin such a way that the clamping screw that with its end is pivotallyconnected to the first clamping ring part by means of a pivot-out jointhas an end-side threaded segment and a collar that is larger in diameterthan the threaded segment and is adjacent to the pivot-out joint andthat the second clamping ring part has a passage through which theclamping screw passes in the active position and has an exit slot forthe clamping screw that makes it possible for the clamping screw topivot out, where the width of said slot, at least in the slot areaadjacent to the first clamping ring part, is smaller than the diameterof the collar and larger than the diameter of the threaded segment ofthe clamping screw. The operating principle of the locking deviceaccordingly consists simply of the fact that for its pivot-out motionthe clamping screw can emerge from the exit slot only when an openingangle is reached at which the expanded collar of the clamping screw hasleft the exit slot, after which the threaded segment, which is smallerin diameter, can pivot out of the exit slot. This design of the lockingdevice is characterized by an especially simple construction.

An especially high degree of operating safety is ensured in the case ofembodiments in which on the second clamping ring part there are surfacearea parts that overlap associated surface area parts of a clamping nutlocated on the threaded segment of the clamping screw in the activeposition in such a way that loosening of the clamping nut causes theclamping ring parts to be spread apart. With this arrangement, theclamping ring parts are forced apart when the clamping nut is loosened.This avoids the risk that, in cases where sometimes, when the clampingnut is loosened, the clamping ring parts are wedged in the clampedposition and do not immediately follow the motion of the clamping nut, asudden spreading motion will occur under pressure. The spreading motionthat is necessarily caused by the loosening of the clamping nut ensuresthat a controlled spreading and thus a controlled reduction of pressurewill occur before pivoting-out of the clamping screw takes place.

In advantageous embodiments, the clamping nut has a longitudinal segmenthoused in the passage of the second clamping ring part with the clampingscrew in the active position; on said longitudinal section are locatedthe area that generates the spreading force when the nut is loosened andthe area over which the clamping force is transferred to step surfacesof the passage when the nut is tightened.

In this case, the arrangement can be designed in such a way that the nutin the area that can be accommodated in the passage has a round shankpart and a ring body that protrudes radially therefrom like a flange,where one flange surface of the ring body forms the end of the shankpart and the surface that transfers the clamping force and its othersurface forms the surface that transfers the spreading force.

With the clamping nut designed in this way, the passage and its exitslot can be stepped in the second clamping ring part in such a way thatthe ring body can be moved into and out of the passage through anenlarged section of the exit slot, where at the end of the enlargedsection the step surfaces that extend into the passage and that transferthe clamping force of the adjacent flange surface of the ring body ofthe nut are formed.

In order to transfer the spreading force acting on the second clampingring part when the nut is loosened, the enlarged section of the exitslot can be formed by grooves made in the two side walls of the slot;the side walls of the grooves form a guide channel for the ring body ofthe clamping nut when pivoting into the active position and pivoting outinto the release position, where the side surfaces of the grooves formthe step surfaces in the passage that transfer the clamping force, aswell as the surface area parts that transfer the spreading force.

The invention is detailed below by means of an embodiment which isillustrated in the drawings.

FIG. 1 shows a perspective side view, in approximately full scale, of anembodiment of the clamp connector according to the invention in theactive operating position in which said connector forms a clampingconnection between welded pipe connection pieces, of which oneconnection piece is visible;

FIG. 2 shows a sectional view of FIG. 1 with a sectional plane runningin the longitudinal direction, where the clamping connection that iscreated of the pipe connection pieces is shown;

FIG. 3 shows an oblique perspective view similar to that of FIG. 1,where the insides of clamping ring parts without pipe connection, piecesare shown, and

FIG. 4 shows an oblique perspective view corresponding to that of FIG.3, where the components that make it possible for a clamping screw topivot out are shown.

FIGS. 1 and 2 show the embodiment in the active functional state, wherea first clamping ring part 1 and a second clamping ring part 3 are in aclamping position, in which they are situated close to one another, inwhich two welded clamping connection pieces 5, of which only one isvisible in FIG. 1, are clamped together. As FIG. 2 shows, a seal 7shaped like an annular disk is located between the connection pieces 5.This seal is made of a plastic material that is compatible with themedium that is located in the pipeline system, for example, anethylene-propylene-diene-rubber (EPDM) or other suitable plasticmaterial. As FIG. 2 best illustrates, oblique surfaces 9 are located onthe end flanges of pipe connection pieces 5 that are of like design. Incooperation with corresponding oblique surfaces on the insides of theclamping ring parts 1 and 3, radial clamping forces exerted by theclamping ring parts 1 and 3 generate an axial clamping force to ensuremutual clamping of the pipe connection pieces 5.

The clamping ring parts 1 and 3, which are connected via a jointarrangement 11, are designed alike in their path from the jointarrangement 11 up to the area near their opposite ends; i.e., in theirmiddle area their shapes correspond to a partial arc. The jointarrangement 11 has a connecting tab 13 (see FIG. 4) which, like clampingring parts 1 and 3 themselves, is made of special steel and is in theshape of a flat, extended plate. This connecting tab 13 is flexiblyconnected in both its end areas to the clamping ring parts 1 and 3 viapivot pins 15.

The clamping device for generating the clamping force is located on theforward activation ends of the clamping ring parts 1 and 3, which areopposite the joint arrangement 11. As the figures show, on thecorresponding end of the first clamping ring part 1, a clamping screw 19is linked via a pivot-out joint 17 in such a way that the clamping screw19 can be pivoted out of an active position, which is shown in FIGS. 1and 3, into release positions, specifically around a pivot axis that isparallel to the longitudinal axis 21 of the pipe (FIG. 2), as FIG. 4illustrates.

In the active position, the clamping screw 19 extends through a passage23 (FIG. 4) that is formed on the activation end of the second clampingring part 3 and that is opened toward the front on the activation end ofthe clamping ring part 3 with an exit slot 25 so that the clamping screw19 can be pivoted outward to switch the clamping device to the releaseposition through the exit slot 25 or can be pivoted into the passage 23to switch into the active position via the exit slot 25.

Due to the special design of the clamping screw 19 and the exit slot 25,the clamping device is equipped with a locking device which allows theclamping screw 19 to pivot out of the active position shown in FIGS. 1and 3 only when safety-related conditions have been fulfilled. As FIGS.1, 3, and 4 show, and as FIG. 4 most clearly illustrates, in the endarea adjacent to the pivot-out joint 17, the clamping screw 19 has acollar 27 whose diameter is larger than that of the threaded segment 29of the clamping screw 19 that is adjacent to the collar 27. Theabove-mentioned locking device is formed by virtue of the fact that thediameter of the collar 27 is larger than the width of the exit slot 25,while the outer diameter of the threaded segment 29 is in turn smallerthan the width of the exit slot 25. This provides simple and reliableassurance that, with the clamping screw 19 in the active position whenthe screw is housed in the passage 23, the clamping screw 19 cannot exitthrough the exit slot 25 because of the diameter of the collar 27 keepsit from passing through the exit slot 25.

If, however, a clamping nut 31, which is engaged with the threadedsegment 29 of the clamping screw 19 to generate the clamping force, isunscrewed to loosen the clamping device to the extent shown in FIG. 4,in which case the clamping ring parts 1 and 3 are separated from oneanother by an opening angle at which the collar 27 of the clamping screw19 can leave the exit slot 25, then the clamping device switches to therelease state since now the threaded segment 29, which is smaller indiameter, can move through the exit slot 25. In other words, pivoting-inof the clamping screw 19 into the passage 23 and pivoting-out to releasethe clamping ring parts of 1 and 3 are thus possible only as a functionof the predetermined opening angle of the clamping ring parts 1 and 3.As the figures also illustrate, the passage 23 and the exit slot 25 arestepped in a special way. In cooperation with the special constructionof the clamping nut 31, the clamping device not only has a lockingdevice that prevents undesired pivoting-out, but a mechanism is alsoformed that forces the clamping ring parts 1 and 3 to open when theclamping nut 31 is unscrewed. For this purpose, on the end of a roundshank part 33 the clamping nut 31 has a flange-like, radially projectingring body 35. As a guide channel through which the ring body 35 moveswhen pivoting into the passage 23 and when pivoting out, the exit slot25 forms an enlarged section 37 at the end area which is located at thetop in the figures. In this enlarged section 37, grooves 39 are made inthe two side walls of the slot 25. The side walls of the grooves 39 formnot only a guide channel for the ring body 35 when the clamping screw 19pivots in and pivots out, but also form step surfaces that are locatedopposite one another. When the clamping nut 31 is tightened, theclamping force of the corresponding end surface of the ring body 35 istransferred via the step surfaces of the grooves 39 that are located atthe bottom in the figures. Conversely, when the clamping nut 31 isloosened, the opposite upper end surface of the ring body 35 transfers aspreading force via the side walls of the grooves 39 that overlap thering body 35, this spreading force necessarily causing an opening motionof the clamping ring parts 1 and 3 to occur when the clamping nut 31 isloosened. This prevents the risk that extensive unscrewing of theclamping nut 31 can occur without a corresponding opening motion of theclamping ring parts 1 and 3, thereby avoiding the risk that, if theclamping nut 31 is completely loosened, in the event that the clampingring parts 1 and 3 are potentially wedged in the clamped position andinitially do not follow the loosening motion of the nut 31, innerpressure might build up and cause abrupt spreading of the clamping ringparts 1 and 3, with the concomitant risks associated therewith.Conversely, the invention ensures that, if the clamping nut 31 isloosened, a corresponding, controlled opening motion of the clampingring parts 1 and 3 will take place.

1. A clamp connector for clamping together connecting pieces (5) onpipelines, with two clamping ring parts (1, 3) which are connected onone end via a joint arrangement (11) and which can pivot around saidjoint arrangement between spread positions and clamped positions inwhich said clamping ring parts are situated close to one another andwith a clamping device that is located on the end of the clamping ringparts (1, 3) opposite the joint arrangement (11), the clamping devicehaving a clamping screw (19) which is pivotable from an active positionin which it works together with said clamping ring parts to generate aclamping force that forces the clamping ring parts (1, 3) into theclamped positions and into a release position which is pivoted outtherefrom, in which the clamping ring parts (1, 3) are released,characterized in that the clamping device has a locking device (25, 27)which in its active state prevents the clamping screw (19) from pivotingout into the release position and, as a function of the spreading of theclamping ring parts (1, 3), passes through a pre-determined openingangle from the active state into a release state that makes it possiblefor the clamping screw (19) to pivot out.
 2. The clamp connectoraccording to claim 1, characterized in that the clamping screw (19)which is pivotally connected with its one end to the first clamping ringpart (1) via a pivot-out joint (17) has an end-side threaded segment(29) and a collar (27) that is adjacent to the pivot-out joint (17) andthat is larger in diameter than the threaded segment and that the secondclamping ring part (3) has a passage (23) through which the clampingscrew (19) passes in the active position and an exit slot (25) for theclamping screw (19) which allows the screw to pivot out, the width ofthis slot, at least in the slot area adjacent to the first clamping ringpart (1), being smaller than the diameter of the collar (27) and beinglarger than the diameter of the threaded segment (29) of the clampingscrew (19).
 3. The clamp connector according to claim 2, characterizedin that on the second clamping ring part (3) there are surface areaparts (39) that in the active position overlap corresponding surfacearea parts of a clamping nut (31) located on the threaded segment (29)of the clamping screw (19) in such a way that loosening of the clampingnut (31) leads to a spreading of the clamping ring parts (1, 3).
 4. Theclamp connector according to claim 3, characterized in that the clampingnut (31) has a longitudinal section (33) that is housed in the passage(23) of the second clamping ring part (3) when the clamping screw (19)is in the active position, on which longitudinal section are located thesurface that generates the spreading force when the nut (31) is loosenedand the surface via which the clamping force is transferred to stepsurfaces of the passage (23) when the nut (31) is tightened.
 5. Theclamp connector according to claim 4, characterized in that in the areathat can be housed in the passage (23) the nut (31) has a round shankpart (33) and a ring body (35) that projects radially therefrom in theshape of a flange, one flange surface of this ring body forming the endof the shank part (33) and the surface that transfers the clamping forceand its other surface forming the surface that transfers the spreadingforce.
 6. The clamp connector according to claim 5, characterized inthat the passage (23) and its exit slot (25) in the second clamping ringpart (3) are stepped in such a way that the ring body (35) can be movedthrough an enlarged section (37) of the exit slot (25) into and out ofthe passage (23) and that at the end of the enlarged section (37) thestep surfaces that extend into the passage (23) are formed that transferthe clamping force of the adjacent flange surface of the ring body (35)of the nut (31).
 7. The clamp connector according to claim 6,characterized in that the enlarged section (37) of the exit slot (25) isformed by grooves (39) made in the two side walls of the slot (25), theside walls of the grooves forming a guide channel for the ring body (35)of the clamping nut (31) when pivoting into the active position andpivoting out into the release position and the side surfaces of thegrooves (39) forming the step surfaces in the passage (23) that transferthe clamping force, as well as the surface area parts that transfer thespreading force.